The present invention relates generally to fuel injection control devices for diesel type internal combustion engines. The invention is more particularly directed to diesel engine injection systems of the type utilizing a separate injector for each engine cylinder, the injectors being driven by a variable high pressure common rail fluid. The present controller generates and regulates the common rail pressure, meters fuel to the injectors, and times the firing of the injectors.
A universal fuel injection system of the type for which the present invention is particularly adapted is shown in U.S. Pat. No. 3,587,547, assigned with the present application to a common assignee, which patent is hereby incorporated by reference. This patent discloses a fuel injection system wherein a separate fuel injector is employed for each engine cylinder and is supplied with discrete metered quantities of fuel which are discharged therefrom upon actuation by an electrical timing signal. The discharge is hydraulically effected by a high pressure common rail fluid acting on an amplifier piston, the common rail pressure being variable to selectively vary the rate of injection in accordance with engine operating conditions.
In the system described in U.S. Pat. No. 3,587,547, a variable high pressure hydraulic fuel pump is utilized to provide the high common rail fluid pressure. The present invention includes integrally within the controller a novel piston type pump for generating this variable common rail pressure and a novel regulator for controlling the rail pressure in accordance with operating conditions. Also described in U.S. Pat. No. 3,587,547 is a universal fuel metering and distributing apparatus, the preferred form of which was that shown in pending application Ser. No. 805,251, now U.S. Pat. No. 3,615,043 issued Oct. 26, 1971 and assigned with the present application to a common assignee. This patent is also incorporated by reference in view of its relationship to the novel fuel metering and distributing apparatus incorporated into the present controller.